The U.N. Security Council has traveled to conflict zones all over the world, but a plan to drive the 15 ambassadors through the streets of New York in a red double-decker bus was deemed too risky, Britain’s U.N. envoy and police said on Tuesday.

Britain’s U.N. mission used the red bus – a public transport fixture on the streets of London – to publicize Britain taking over the rotating presidency of the Security Council for the month of June and to promote tourism in the United Kingdom.

“The original idea was that we would drive the bus from my residence to the Security Council with the 15 ambassadors but that was blocked by the NYPD (New York Police Department) who said driving 15 ambassadors in big bus was a security threat,” Britain’s U.N. Ambassador Mark Lyall Grant told reporters.

Britain, France, the United States, Russia and China are permanent veto-wielding Security Council members, while Azerbaijan, Togo, Australia, Argentina, Luxembourg, Korea, Pakistan, Guatemala, Morocco and Rwanda are elected members for two-year terms.

NYPD spokesman Paul Browne said the department’s Intelligence Division had recommended against making “so many high-value targets” vulnerable to attack in an open vehicle lacking security.

“It sounded like fun,” Browne said of the planned bus ride. “We were the wet blanket, but a security blanket all the same.”

Some U.N. envoys took a ride on the bus around a traffic circle inside the U.N. compound instead, Lyall Grant said.